The present invention relates to an imaging assembly for processing photosensitive media that includes a plurality of microcapsules that encapsulate coloring material. The present invention further relates to a media cartridge having a linkage assembly that is responsive to ambient conditions in the cartridge.
Image forming devices which process a photosensitive media that includes microcapsules which encapsulate coloring material are known. In these imaging devices the microcapsules are exposed to a radiation based on image information. The microcapsules, whose mechanical strength can change when exposed to light, are ruptured by means of a crushing pressure, whereupon the coloring material and other substances encapsulated in the microcapsules flow out and development occurs. For example, some systems use a pair of upper and lower nip rollers to apply pressure. In these systems, the photosensitive media is passed between the pair of upper and lower nip rollers which apply pressure to the microcapsules to rupture the microcapsules and begin development. Imaging devices that employ microencapsulted photosensitive compositions are disclosed in U.S. Pat. Nos. 4,399,209, 4,416,966, 4,440,846, 4,766,050, 5,783,353, and 5,916,727.
A problem in processing photosensitive media having microencapsulated color forming material is that printing and/or imaging can be adversely affected by ambient conditions. That is, ambient conditions around a printing housing, around the photosensitive media, or in the cartridge which carries the photosensitive media can adversely affect subsequent printing or development of the image. More specifically, ambient conditions such as humidity around the printer housing, at the photosensitive media or in the cartridge which houses the photosensitive media can have adverse affects on the chemicals of the coloring material, the encapsulating material, and/or the photosensitive media. Further, the degree of hardening or curing of the microcapsules and the consequent increase in viscosity of the microcapsule varies with a change in humidity. As a result, photographic characteristics such as speed, minimum and maximum density, fogging density and full color imaging can be adversely affected.
The present invention provides for an image forming assembly and method for processing photosensitive media that overcomes the above-mentioned drawbacks. More specifically, the present invention relates to an imaging device in which light sensitive media that contains light sensitive, rupturable microcapsules can be first exposed and then developed by applying pressure to the light sensitive media. In the image forming device of the present invention, print image quality can be improved by sensing ambient conditions such as humidity in the printer, directly from the media, or in the cartridge which carries the media, and adjusting at least one adjustable parameter based on the sensed ambient condition. As an example, in response to a sensed humidity condition, a controller or development member of the present invention can adjust the amount of pressure applied to the microcapsules.
As indicated above, in the imaging device of the present invention, the photosensitive medium contains light sensitive, rupturable microcapsules that are exposed and then developed by the application of pressure using a stylus or pinch rollers to rupture unexposed microcapsules. Thereafter, the developed print is fixed with heat supplied by a heater in the imaging device. In the present invention, the level of relative humidity can be sensed inside and/or outside of the printer, in the media cartridge or directly on the photosensitive media, and then at least one of the parameters of light exposure, developing pressure, printing speed or fixing temperature can be adjusted automatically on the basis of the relative humidity level to provide an improved image. As an example, by adjusting the printing speed for a printer, the so called xe2x80x9cdark timexe2x80x9d which is the time between exposure and development will be changed. The dark time affects the hardness of microcapsules and therefore their crushability. Also, within the context of the present invention, the concept of sensing the level of relative humidity on the photosensitive media refers to sensing the moisture content on the photosensitive media or material.
The imaging device of the present invention also includes an improved pressure assembly for applying a uniform pressure to the photosensitive media.
Accordingly, the present invention relates to an imaging assembly which comprises a media cartridge for holding a stack of photosensitive media therein, with the media cartridge comprising a linkage assembly, at least a portion of the linkage assembly being made of a material that is responsive to ambient conditions within the cartridge; and an image forming device which is adapted to receive the media cartridge in an insertion position to permit an insertion of photosensitive media from the media cartridge into the image forming device. The image forming device comprises a pressure assembly for applying a pressure to the photosensitive media to develop an image on the photosensitive media. In the insertion position the linkage assembly is adapted to operationally cooperate with the pressure assembly to control an amount of pressure applied by the pressure assembly to the photosensitive media based on the ambient conditions in the cartridge.
The present invention further relates to a cartridge for holding photosensitive media therein. The cartridge comprises a linkage assembly having at least a portion which is responsive to ambient conditions in the cartridge. The linkage assembly is adapted to cooperate with a development member in an imaging device, such that a development of images on photosensitive media inserted from the cartridge into the imaging device is controlled based on ambient conditions in the cartridge.
The present invention further relates to a method of controlling a development of photosensitive media, which comprises the steps of: providing a linkage member in a cartridge which holds photosensitive media therein, with at least a portion of the linkage member being made of a material that is responsive to ambient conditions in the cartridge; and inserting the cartridge in an imaging device to permit a passage of the photosensitive media from the cartridge to the imaging device, such that the linkage member cooperates with a development member in the imaging device to control development of images on the photosensitive media in the imaging device based on ambient conditions in the cartridge.